py/stream: Switch stream close operation from method to ioctl.

This patch moves the implementation of stream closure from a dedicated
method to the ioctl of the stream protocol, for each type that implements
closing.  The benefits of this are:

1. Rounds out the stream ioctl function, which already includes flush,
   seek and poll (among other things).

2. Makes calling mp_stream_close() on an object slightly more efficient
   because it now no longer needs to lookup the close method and call it,
   rather it just delegates straight to the ioctl function (if it exists).

3. Reduces code size and allows future types that implement the stream
   protocol to be smaller because they don't need a dedicated close method.

Code size reduction is around 200 bytes smaller for x86 archs and around
30 bytes smaller for the bare-metal archs.

1 files changed, 12 insertions, 15 deletions

diff --git a/ports/esp32/modsocket.c b/ports/esp32/modsocket.c
index 31d153964..8b3c28063 100644
--- a/ports/esp32/modsocket.c
+++ b/ports/esp32/modsocket.c
@@ -83,19 +83,6 @@ void check_for_exceptions() {
     }
 }
 
-STATIC mp_obj_t socket_close(const mp_obj_t arg0) {
-    socket_obj_t *self = MP_OBJ_TO_PTR(arg0);
-    if (self->fd >= 0) {
-        int ret = lwip_close_r(self->fd);
-        if (ret != 0) {
-            exception_from_errno(errno);
-        }
-        self->fd = -1;
-    }
-    return mp_const_none;
-}
-STATIC MP_DEFINE_CONST_FUN_OBJ_1(socket_close_obj, socket_close);
-
 static int _socket_getaddrinfo2(const mp_obj_t host, const mp_obj_t portx, struct addrinfo **resp) {
     const struct addrinfo hints = {
         .ai_family = AF_INET,
@@ -450,6 +437,16 @@ STATIC mp_uint_t socket_stream_ioctl(mp_obj_t self_in, mp_uint_t request, uintpt
         if (FD_ISSET(socket->fd, &wfds)) ret |= MP_STREAM_POLL_WR;
         if (FD_ISSET(socket->fd, &efds)) ret |= MP_STREAM_POLL_HUP;
         return ret;
+    } else if (request == MP_STREAM_CLOSE) {
+        if (socket->fd >= 0) {
+            int ret = lwip_close_r(socket->fd);
+            if (ret != 0) {
+                *errcode = errno;
+                return MP_STREAM_ERROR;
+            }
+            socket->fd = -1;
+        }
+        return 0;
     }
 
     *errcode = MP_EINVAL;
@@ -457,8 +454,8 @@ STATIC mp_uint_t socket_stream_ioctl(mp_obj_t self_in, mp_uint_t request, uintpt
 }
 
 STATIC const mp_map_elem_t socket_locals_dict_table[] = {
-    { MP_OBJ_NEW_QSTR(MP_QSTR___del__), (mp_obj_t)&socket_close_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_close), (mp_obj_t)&socket_close_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR___del__), (mp_obj_t)&mp_stream_close_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_close), (mp_obj_t)&mp_stream_close_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_bind), (mp_obj_t)&socket_bind_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_listen), (mp_obj_t)&socket_listen_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_accept), (mp_obj_t)&socket_accept_obj },